Identity, nature and ground

What does the qualitative identity of objects consist in? A standard response is that it consists in the possession of properties and relations. If all of an object’s properties and relations are specified, all there is to be specified about its qualitative as opposed to its numerical identity will have been specified. Another response adds that kinds, conceived of as an irreducible category of entity, also play a part in fixing the qualitative identities of objects. In what follows, two arguments are offered according to which these views are insufficient. Both lead to the conclusion that the qualitative identities of objects consist in part in their natures being grounded in what differs from entities, that is to say in something like conditions for the possibility of entities. The idea of such grounding will be clarified, and some of the criteria of adequacy for theses about it will be spelled out. Further, the implications of the claim that the natures of objects are grounded for the problems of the one and the many will be discussed.